"...the nature and extent of the punishment must be carefully evaluated and decided upon and ought not go to the extreme of executing the offender except in case of absolute necessity: In other words, when it would not be possible otherwise to defend society. Today, however, as a result of steady improvements in the organization of the penal system, such cases are very rare, if not practically non-existent.

I might add that the Iraq war wasn't just opposed by the Catholic faith. It was also opposed by the leaders of the "Episcopal, Evangelical Lutheran, United Methodist, Presbyterian (USA) and Orthodox churches." Bush, by the way, is a member of the United Methodist church.